求一SQL查询条件判断

Question

我有一表记录如下: 表名 A表
   C日期         D日期
   2009-02-03    2009-02-04
   2009-02-04    2009-02-02我要写一语句,譬如查询 2009-02-04 这天有哪几条记录, 要求是 以两个日期中大者参加判断.如查询 2009-02-04  结果是两条记录都 显示,因为两个最大日期都为 2009-02-04  ,如查询2009-02-03 则不返回任何记录.
decare @rq datetime
set @rq='2009-02-04'
select * from a表 不知后面条件该如何写.谢谢

Answer 1

select *
from tb
where
datediff(dd,case when c>d then c else d end,'2009-02-03')=0

Answer 2

---测试数据---
if object_id('[tb]') is not null drop table [tb]
go
create table [tb]([C] datetime,[D] datetime)
insert [tb]
select '2009-02-03','2009-02-04' union all
select '2009-02-04','2009-02-02'
 
---查询---
select *
from tb
where
datediff(dd,case when c>d then c else d end,'2009-02-03')=0
/**
C                                                      D                                                      
------------------------------------------------------ ------------------------------------------------------ （所影响的行数为 0 行）
**/select *
from tb
where
datediff(dd,case when c>d then c else d end,'2009-02-04')=0
/**
C                                                      D                                                      
------------------------------------------------------ ------------------------------------------------------ 
2009-02-03 00:00:00.000                                2009-02-04 00:00:00.000
2009-02-04 00:00:00.000                                2009-02-02 00:00:00.000（所影响的行数为 2 行）
**/

Answer 3

select *
from tb
where
datediff(dd,C,'2009-02-03')=0 OR datediff(dd,D,'2009-02-03')=0